The present invention concerns a non-extensible articulated bracelet, in particular for a watch, including a plurality of decorative annular elements which are sensitive to compression or shocks, said decorative elements being strung onto a central core formed by an inner chain of links connected to each other by pivoting axes and designed to co-operate with each other and with the decorative elements to prevent any accidental compression or shock from breaking said elements.
The invention concerns more particularly a bracelet of this type wherein the decorative elements are made of a material having very high resistance to abrasion, but lower resistance to shocks, such as ceramic based composites.
Non-extensible bracelets having a central core, made of a base material with an essentially mechanical function, completely or partially masked by a decorative outer element made of free links made of a more noble material have already been disclosed in various documents of the prior art, certain of which also have the object of preventing excessive bending likely to damage the outer element.
French Patent No. 2 502 916 discloses a watch bracelet formed of an inner chain onto which decorative elements, open on the wrist side, are freely strung on. The inner chain is formed of solid links each including a stud portion and a slot portion to allow them to be fitted inside each other and keeping them assembled by means of a pin. The face of the stud opposite the slot has a certain inclination in order to limit the range of movement of an inner link with respect to the next link to fit the natural curve of the wrist. Because of the play which must necessarily exist between each decorative element, when the bracelet is bent a decorative element may not cover the corresponding link of the inner chain perfectly and may be damaged when the bracelet is bent.
In order to overcome the aforecited drawback European Patent No. 0 549 979 proposes a device wherein the decorative elements are enveloping, leaving free a central passage provided laterally with stops and they are positioned precisely above each link by blocking bars. The opposite faces of the decorative elements have complementary rounded shapes but no means are provided, on the inner chain, able to limit the range of movement thereof, which does not eliminate the risk of breakage by excessive bending.
The non-extensible bracelet disclosed in European Patent No. 0 736 480 includes a relatively complex articulation device between two successive links including two pins connected by linking elements which also determine the authorised bending angle, each enveloping decorative element being held on this articulation device by an insert passing through said element and being held snap fitted by the pins.
The object of the present invention is to overcome the drawbacks of this prior art by providing a non-extensible articulated bracelet, wherein the links of an inner chain co-operate with each other and with the decorative elements strung onto them to prevent or limit the risk of said decorative elements being compressed when the bracelet is bent or in the event of an accidental shock, for example by dropping to the ground a watch fitted with such a bracelet.
The present invention therefore concerns a bracelet formed of enveloping decorative elements mounted on a non-extensible articulated inner chain formed of links the particular shape of which, by co-operating with the structures of the passages through the decorative elements, allows the angular range of movement of a link with respect to the next link to be limited to an angle xcex1 in a vertical plane passing through the longitudinal line of symmetry X-Xxe2x80x2 of the bracelet.
Each decorative element includes, on a part of the depth of the through passage, on the one hand a central rib, and on the other hand two lateral edges connecting the cap, i.e. the visible part, to feet made as an overthickness on the bottom, said feet forming two symmetrical grooves with respect to the line X-Xxe2x80x2.
Each link includes a central slot which is complementary to the rib of a decorative element and the bottom of which forms a bridge through which a pin hole passes. The bridge connects two symmetrical coupling elements, the main body of which has a width substantially smaller than the distance between the central rib and a lateral edge. Each coupling element has at one end a lateral arm provided with a pin hole, extending beyond the main body over a distance corresponding to the thickness of one edge and forming with the bridge a recess which is complementary to an extension of the opposite end, through which a pin hole also passes. The edges of the pin holes or the edges of the recesses and extensions are provided with blocking means limiting the bending angle of a link with respect to the next link.
According to a first embodiment, the blocking means are formed at each end of the pin hole of the bridge by two annular stops having vertical shoulders which cooperate with annular stops provided at the ends facing the holes of the two extensions, said stops having shoulders forming an angle of less than 180xc2x0 one being vertical on the cap side, the other being inclined at an angle xcex1 on the bottom side.
According to another embodiment the blocking means are formed at the end of each extension by a lug bent at an angle xcex1 on the bottom side, said lug co-operating with a recess of complementary shape, provided on the bottom side in the thickness of each coupling element and joining an edge of the recess.
It will also be observed that the presence of feet between the bottom and the edges and the rib allow a certain play enabling bending slightly greater than the value xcex1 to be absorbed, without exerting any stress on the decorative element.